Preheat the oven to 200°C fan. On a large baking tray, toss together the cauliflower, lentils, onion, harissa and olive oil, a generous pinch of salt and plenty of black pepper; spread everything out evenly in a single layer. Place the tray in the oven and cook for 25–30 minutes, until the cauliflower is golden and charred at the edges.

Meanwhile, make the croutons. Toast the sourdough and rub both sides of each slice with the raw garlic; cut into bite-sized pieces. Warm a drizzle of olive oil in a large frying pan set over medium heat; add the sourdough, pistachios and pumpkin seeds, and cook for 5–6 minutes until golden. Season with flaky sea salt and set aside to cool.

Make the dressing. Whisk together all of the dressing ingredients, along with 2 tablespoons of water to loosen; season to taste with a pinch of flaky sea salt and black pepper.

Tip the cauliflower mixture into a large serving dish or salad bowl and toss through ½ of the dressing, followed by the radishes, rocket and seedy garlic croutons. To serve, drizzle the remaining dressing over the top.